Abstract

A multi-image focus of attention mechanism has been developed that can
quickly distinguish raised objects like buildings from structured background
clutter typical to many aerial image scenarios.
The underlying approach is the space-sweep stereo method,
in which features from multiple images are
backprojected onto a virtual, horizontal plane that is
methodically swept through the scene.
Backprojected gradient orientations from multiple
images are highly correlated when they come from
scene locations containing structural edges that
are roughly horizontal, like building roofs and terrain;
otherwise, they tend to be uniformly distributed.
These observations are used to define a
structural salience measure that can determine whether
a given volume of space contains a statistically
significant number of structural edges,
without first performing precise reconstruction of those edges.
The utility of structural salience for computing focus of
attention regions is illustrated on sample data
from Ft.Hood, Texas.